Sleepiness is a common presenting complaint in sleep centers, and sleep disordered breathing is a common cause; however, insufficient sleep occurs in over one third of US adults, but is not often addressed. This proposal is based on the premise that insufficient sleep contributes to sleepiness in patients with SDB, and may account for the variability in response to PAP therapy in patients with sleepiness and mild SDB. The objective is to determine the treatment that results in the greatest benefit to patients. We will also explore differences in blood pressure (BP outcomes) in those with hypertension. We will address the following Specific Aims: Specific Aim 1: demonstrate the effectiveness of a cognitive-behavioral sleep-time extension (STE) program compared to PAP in increasing objective alertness. Primary hypothesis 1 is that STE will be non- inferior to PAP therapy in increasing objective alertness [number of psychomotor vigilance testing (PVT) lapses]. If signs of superiority of STE over PAP are observed, we will test the Secondary Hypothesis that STE is superior to PAP in increasing objective alertness among patients with mild SDB. Specific Aim 2: To demonstrate the effectiveness of STE compared to PAP in reducing daytime sleepiness and fatigue. Primary Hypothesis 2 is that STE will be non-inferior to PAP therapy in reducing daytime sleepiness and fatigue. If signs of superiority of STE over PAP are observed, we will test the Secondary Hypothesis that STE will be superior to PAP in reducing daytime sleepiness and fatigue among patients with mild SDB. We also propose Exploratory Aim 3: To evaluate the effectiveness of STE compared to PAP in improving endothelial function and reducing blood pressure among the subset of patients with hypertension. Exploratory Hypothesis 3A is that, among patients hypertension, STE will be non-inferior to PAP in reducing blood pressure, and Exploratory Hypothesis 3B is that, among patients with hypertension, STE will be non-inferior to PAP in improving endothelial function. If signs of superiority of STE over PAP are observed, we will then we will test the superiority of STE to PAP in improving endothelial function and reducing blood pressure. We will address these aims by comparing the 4-session STE program to PAP therapy (with a 4-session PAP adherence program). We will also include a 4-session non-directive equal attention sleep education ?control? (SEC) program. The STE program includes behavioral, cognitive and motivation enhancement strategies to increase sleep duration. Key outcomes will be measured pre- and post-treatment (1 month) and again at 3-months follow-up. Results will have significant impact regardless of the findings. If STE is superior to PAP in improving outcomes, patients with mild SDB should first be encouraged to obtain adequate sleep prior to initiation of PAP. If STE is non-inferior, either treatment may be viable, and can be based on patient preference. Conversely, superiority of PAP means a substantial emphasis on troubleshooting and enhancing acceptance and adherence is warranted.